Method of making sound records



Patented Sept. 25, 1934 PATENT? OFFICE i v 1,974,710 METHOD OF MAKING SOUND RECORDS Berthold Freund, Berlin-Schcneberg, Germany,

assignor to Internationale Tobis Maatschappij N. V., Amsterdam, Netherlands No Drawing.

Original application August 10, 1

1929, Serial No. 385,000. Divided and this application December 8, 1931, Serial No. 579,755. In Germany August 20, 1928 1 Claim.

My invention relates to the manufacture of talking picture films by making separate sound and picture records as described in my co-pending application for patent of the United States,

5 1; Ser. No. 385,000, filed August 10, 1929, for Method of and apparatus for making sound records of which the present application is a division.

It is an object of my invention to provide an improved method of making talking picture films,

i. e. films having a sound and a picture record.

To this end, I perform my method in two stages, as follows:

1. The pictures are recorded by photographic, and the sound is recorded by magnetic means;

2. The magnetic sound record is re-recorded as an optical sound record on the film on which the pictures have been recorded.

A magnetic sound record is preferable to an optical sound record for reasons which will be set out below. On the other hand, magnetic sound records lack durability and this is why the magnetic sound record, in stage 2, is re-recorded as an optical sound record. The finished film is like any normal talking and picture film and may '25; be reproduced in any normal apparatus.

The individual stages, 1 and 2, are old, but I was the first to see the advantages of magnetic sound recording as compared with optical sound recording, under certain dimcult conditions. The

equipment for the magnetic sound recording is so readily portable that it permits following an object, for instance, a wild animal, in a primeval forest, or other difiicult country, with the picture camera and the magnetic equipment. Another advantage of the magnetic sound-recordingequipment is that it permits hearing the sound record immediately after it has been made, and at the point where it has been made, so that a new sound record can be prepared in the field if it is found that the record which has been made,

is not satisfactory. All the operator has to carry, is a supply and the equipment for making the magnetic sound record.

The supply consists of a small reel of steel 3 wire and the equipment is not larger than a portmanteau. Obviously, for outdoor work this is an important point in the favor of the magnetic recording of the sound, for the optical sound-recording system, with its large and heavy film reels for the supply and the standby, and its correspondingly large equipment, is too cumbersome to be used under dificult conditions, for instance, in the mountains, in dense forests, etc.

It is obvious that the initial cost of the large and heavy optical equipment far exceeds that of the small and light magnetic equipment.

Another advantage of the magnetic sound-recording is that the operator can hear the sound record immediately without requiring a large battery or an amplifier, while in the optical sound-recording system this is impossible. Consequently, if a magnetic record is not satisfactory, the operator ascertains this and may make another record immediately. In the optical sound-recording systern, he will only find out at the laboratory whether his record was good or not.

The facility of ascertaining immediately whether a magnetic sound record is good or not is also very important for the recording of stage scenes at the studio, as the sound record can be heard before the stage setting is changed and the actors have departed.

As mentioned, magnetic sound records have the drawback of being less durable than optical ones. 75, Another drawback is that they cannot be repro- Y duced in normal apparatus. Therefore, in stage 2, the magnetic sound record is re-recorded as an optical sound record, to obtain a normal talking picture film.

It is old to make separate records of pictures and the sounds accompanying them by photographing the pictures, recording the sounds by non-optical, i. e. magnetic means, and reproducing the two individual records together.

It has also been attempted to connect the individual sound and picture records mechanically but this is an extremely diificult problem not only because it is very difficult to connect the picture and sound records satisfactorily but also because magnetic sound records are very delicate and will be damaged if treated without care, and lack durability, as mentioned.

According to my invention these drawbacks are eliminated by obtaining a sound record by magnetic means, re-recording into a photographic record and combining this photographic record with the picture record.

In reducing my invention to practice I make separate picture and sound records, as described in my said co-pending application, by photographing the pictures and making the sound records by magnetic means, and re-recording such sound records into photographic records. The photographic sound records together with the pictures are reproduced by normal apparatus.

The combination of the pictures with the photographed sound records may be effected in various ways. For instance, the photographic copy of the magnetic sound record is made in an area of the picture film which had been covered up when the pictures were made, and the copy and the pictures are developed together. It is also possible to employ the magnetic sound record directly for optically recording the -sounds on the picture record, eliminating the necessity of making an extra copy of the sound record -zor to leave open an area on the positive picture film positive copies.

I claim:

The method of producing motion picture films having combined picture and sound records thereon for photographic ,reproductionwhich comprises recording the sound efiects, magnetically" at the taking of the picture record, and

re-recording the magnetic sound record photo- 7 graphically on the same film as the picture rec- 0rd, in synchronism with said picture record.

and to develop the two records together; as; a

cBERTHOLD FREUND.

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